**2.2. Pliny the elder**

6 New Approaches to the Study of Marine Mammals

soul.

respectively).

566b2-5).

2012.

have bones (*HA* 516b11).

591b9-15), and swim fast (*HA* 591b29).

classification of these animals.

Aristotle followed his teacher Plato in classifying animals by progressively dividing them based on shared characters. This is an embryonic form of today's classification more fully developed by Linnaeus. The reason he ordered the different "genera" the way he did was because he considered "vital heat" (characterized by method of reproduction, respiration, state at birth, etc.) as an index of superiority placing humans at the very top. Men were superior to women because they had more "vital heat." On this he followed Hippocrates's ideas, since the Greek physician thought there was an association between temperature and

Yet he was not fully satisfied by this approach given that a number of "genera" had characters that were shared across groups, particularly when compared with their habitats. For example, both fishes and cetaceans had fins, but they differ markedly on other characters such as reproduction (oviparous vs. viviparous) or organs (gills vs. lungs,

Many of Aristotle's observations about cetaceans remain accurate. In terms of internal anatomy he mentioned that they have internal reproductive organs (*HA* 500a33-500b6), that dolphins, porpoises, and whales copulate and are viviparous, giving birth to between one and two offsprings having two breasts located near the genital openings that produce milk (*HA* 504b21), that dolphins reach full size at the age of 10 and their period of gestation is 10 months, show parental care, some may live up to 30 years and this is known because fishers can individually identify them by marks on their bodies (*HA* 566b24), and that dolphins

Regarding behavior and sensory organs he said that dolphins have a sense of smell but he could not find the organ (*HA* 533b1), that dolphins can hear despite the lack of ears (*HA* 533b10-14), produce sounds when outside the water (*HA* 536a1), that dolphins and whales sleep with their blowhole above the surface of the water (*HA* 537a34), are carnivorous (*HA*

He held that cetaceans are not fishes because they have hair, lungs (*HA* 489a34), lack gills, suckle their young by means of mammae, they are viviparous (*HA* 489b4), and that their bones are analogous to the mammals, not fishes. Still they he calls them "fishes" (*HA*

These basic Aristotelian biological descriptions persisted for good and for bad until Charles Darwin's evolutionary work. On one hand his descriptions were so accurate that Darwin admired Aristotle, to the point that he said privately that the intellectual heroes of his own time "were mere schoolboys compared to old Aristotle."5 Yet the fact that Aristotle saw the natural world as fixed in time with no room for evolution and that he kept calling cetaceans "fishes," would delay intellectual progress for many centuries when it came to the

<sup>5</sup> Darwin Correspondence Database, http://www.darwinproject.ac.uk/entry-11875 accessed on 25 Feb

Pliny the Elder6 was the son of an equestrian (the lower of the two aristocratic classes in Rome) and was educated in Rome. After serving in the military he became a lawyer and then a government bureaucrat. In these positions he travelled not only throughout what is Italy today but also what it would later became Germany, France and Spain as well as North Africa (Reynolds 1986).

He wrote a 37-volume *Naturalis Historia7* (ca. 77-79) in which according to himself he had compiled "20,000 important facts, extracted from about 2000 volumes by 100 authors" and was written for "the common people, the mass of peasants and artisans, and only then for those who devote themselves to their studies at leisure" (Preface 6). This is the earliest known encyclopedia of any kind, which has been interpreted as a Roman invention in order to compile information about the empire (Naas 2002, Murphy 2004). It was a rather disorganized book, whose prose has been criticized by many (Locher 1984). Pliny seemed to be more interested in what appeared to be curiousities than what were facts. This is a big collection of facts and fictions, based mostly said on things said by others.

He devoted 9 of the 37 volumes to animals and ordered them according to where they live. Volume IX (*Historia Aquatilium*) of *Naturalis Historia* is devoted to aquatic creatures, whether living in oceans, rivers or lakes, whether vertebrate or invertebrate, real or mythical. Based on their size he categorized as "monster" anything big, whether it is a whale, a sawfish or a tuna (IX 2,3).

He grouped together all known species of cetaceans (*cete*) but constantly mixed their descriptions with those of other marine mammals such as seals as well as with cartilaginous fishes, such as some sharks (*pristis*). Pliny mentioned the three species cited by Aristotle: dolphins (*delphinus*, probably a combination of striped dolphin [*Stenella coeruleoalba*] and the common dolphin [*Delphinus delphis*], IX 12-34), porpoises (*porcus marinus*, the harbor porpoise [*Phocoena phocoena*], IX 45) and whales (*ballaena*, possibly a combination of large toothless whales [mysticetes] IX 12-13). Then he added a few more: the *thursio* or *tirsio* (probably the bottlenose dolphin, *Tursiops truncatus* IX 34), the *physeter* (probably the sperm whale [*Physeter macrocephalus*] IX 8) found in the "Gallic Ocean" (probably the Bay of Biscay, IX 3, 4), the *orca* (probably the killer whale [*Orcinus orca*] IX 12-14), and the river dolphin from India (possibly *Platanista gangetica*, IX 46). He also mentioned some mythical creatures such as *Homo marinus* (Sea-Man, IX 10) and the *Scolopendra marina* (IX, 145) a mythical

<sup>6</sup> *b*. as Gaius Plinius Secundus 23/24 CE in what is now Como, Italy; *d*. 25 August 79 CE near Pompeii, Italy.

<sup>7</sup> I used the version available at:

http://www.perseus.tufts.edu/hopper/text?doc=Plin.+Nat.+toc&redirect=true

organism whose legend may be based on polychaetes, marine annelids characterized by the presence of many legs (Leitner 1972, p. 218).

When Whales Became Mammals:

The Scientific Journey of Cetaceans From Fish to Mammals in the History of Science 9

Belon8 was the first author studying marine mammals in this historical period. Little is known about his family and early years. He traveled extensively throughout Europe and the Middle East, including the Arabian Peninsula and Egypt. Among the places he visited were Rome where he met two other ichthyologists, Rondelet and Salviani (see below). He studied medicine at the University of Paris and botany at the University of Wittenberg, Germany. He served as a doctor and apothecary for French kings, as well as a diplomat, traveler, and

His *L'Histoire Naturelle des Estranges Poissons Marins* (1551) was the first printed scholarly work about marine animals. This book was expanded and published in French in 1555 as *La* 

Belon not only reproduced information from Aristotle and Pliny but also added his own observations including comparative anatomy and embryology. For him "fish" was anything living in the water. He divided "fishes" in two large groups: the first was "fish with blood" (as Aristotle had done) that included not only actual fishes but also cetaceans, pinnipeds, marine monsters and mythical creatures such as the "monk fish," as well as other aquatic vertebrates such as crocodiles, turtles, and the hippopotamus. He called a second group "fishes without blood" and consisted of aquatic invertebrates (see also Delaunay 1926).

He ordered what we know as cetaceans today in a vaguely descending order based on size: *Le balene* (mysticete whales, although in the illustration he depicted a cetacean with teeth), *Le chauderon* (sperm whale? although he mentions the sawfish), *Le daulphin* (common dolphins on which he devoted 38 pages of this 55-page book), *Le marsouin* (porpoise), and *L'Oudre* (bottlenose dolphin) (for a rationale on the identification of these species see Glardon 2011, p. 393-398). He dissected common dolphins (*D. delphis*) and porpoises (*P. phocaena*) acquired at the fish market in Paris brought in by Normandy fishers, and probably a bottlenose dolphin (*T. truncatus*) as well. He described these marine mammals as having a placenta, mammae, and hair on the upper lip of their fetus. Belon wrote that apart from the presence of hind limbs, they conform to the human body plan with features such as the liver, the sternum, milk glands, lungs, heart, the skeleton in general, the brain, genitalia. He also dealt with issues of breathing and reproduction (although from the description it is clear that he never saw one of these animals giving birth, since he depicted the newborn surrounded with a membrane). He drew the embryo of a porpoise and the skull of a dolphin (Fig. 1). Despite all this he did not make the connection between cetaceans and "viviparous quadrupeds" and based his entire classification on environmental foundations, as he made clear in the introduction of his work.

Wotton9 was the son of a theologian who did general studies at Oxford and studied medicine and Greek at Padua (1524-6). He was a practicing physician who published *De* 

<sup>8</sup> *b*. 1517, Soultière, near Cerans, France; *d*. April 1564, Paris, France. <sup>9</sup> *b.* 1492, Oxford, England; *d.* 5 October 1555, London, England.

as a secret agent (he was murdered under strange circumstances) (Wong 1970).

*Nature et diversité des poissons* including 110 species with illustrations for 103 of them.

**4.1. Pierre Belon** 

**4.2. Edward Wotton** 

Pliny recognized that neither whales nor dolphins have gills, that they suckle from the teats of their mothers, and that they are viviparous. In addition to these true facts copied from Aristotle, he mentioned exaggerations such as whales of four jugera (ca. 288 m) in length that because of their large size "are quite unable to move" (IX 2,3). In addition to some of the biological facts mentioned by Aristotle, Pliny adorns his narrative with all kind of casual tales about interactions between cetaceans and humans.

By lumping together all kinds of aquatic organisms it is hard to distinguish what he called "fish" and what he did not (see for example IX 44-45). His classification took a step back from Aristotle because he did not try for a comprehensive classification of animals. He failed to compare organisms based on shared or divergent characters. Many times he ordered creatures based on size, from the largest to the smallest. Yet, his work had great influence for 1700 years, which was unfortunate because he was an uncritical compiler of other people's writings (even if they were contradictory). Pliny also created a number of unfounded impressions about the reality of nature. His only positive contribution was that he established the norm of always citing the sources of his information (in actuality 437 authors, whose works, in some cases, are no longer available).
